How to Password Protect a Vim File in Linux

Vim is a popular, feature-rich and highly-extensible text editor for Linux, and one of its special features is support for encrypting text files using various crypto methods with a password.

In this article, we will explain to you one of the simple Vim usage tricks; password protecting a file using Vim in Linux. We will show you how to secure a file at the time of its creation as well as after opening it for modification.

In case you enter a wrong password (or no key), you’ll see some junk characters.

Vim Content Encrypted

Setting a Strong Encryption Method in Vim

Note: There is a warning indicating that a weak encryption method has been used to protect the file. Next, we’ll see how to set a strong encryption method in Vim.

Weak Encryption on Vim File

To check the set of cryptmethod(cm), type (scroll down to view all available methods):

:help 'cm'

Sample Output

*'cryptmethod'* *'cm'*
'cryptmethod' 'cm' string (default "zip")
global or local to buffer |global-local|
{not in Vi}
Method used for encryption when the buffer is written to a file:
*pkzip*
zip PkZip compatible method. A weak kind of encryption.
Backwards compatible with Vim 7.2 and older.
*blowfish*
blowfish Blowfish method. Medium strong encryption but it has
an implementation flaw. Requires Vim 7.3 or later,
files can NOT be read by Vim 7.2 and older. This adds
a "seed" to the file, every time you write the file
options.txt [Help][RO]

You can set a new cryptomethod on a Vim file as shown below (we’ll use blowfish2 in this example):

:setlocal cm=blowfish2

Then press [Enter] and :wq to save the file.

Set Strong Encryption on Vim File

Now you should not see the warning message when you open the file again as shown below.

Always remember to appropriately secure text files that could contain secret info such as usernames and passwords, financial account info and so on, using strong encryption and a password. Use the feedback section below to share any thoughts with us.

Aaron Kili is a Linux and F.O.S.S enthusiast, an upcoming Linux SysAdmin, web developer, and currently a content creator for TecMint who loves working with computers and strongly believes in sharing knowledge.

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1. How can I reset the password using the current password?
2. What If I forget the password later. Is there any way to reset the password without entering the old password? I mean is there something like security questions etc

Do not forget the password, otherwise you’ll not be able to view the contents of the file again. And to update the password, open the file for editing and type [Esc] and :X then save changes to the file like this :w before closing it.